Automatic control for vehicle headlights



March 21, 1939. R E, ALLEY 2,150,900

. AUTOMATIC CONTROL FOR VEHICLE HEADLIGHTS Filed May 5, 1937 kg k Way.

2] MW a 6 4/5554 A: 41 4 5);

Patented Mar. 21, 1939 g UNITED STATES PATENT OFFICE AUTOMATIC CONTROL FOR VEHICLE HEADLIGHTS Russel E. Alley, Austin, Minn assignor of onethird to Francis N. Earl, Austin, Minn., and onethird to Bennett J. Porter, Albert Lea, Minn.

Application May 5, 1937, Serial No. 141,002

3 Claims. (Cl. 171-97) This invention relates to vehicle lights and has movable contact 2| selectively engageable with special reference to an automatic control for the contacts 22 and 23. From the contact 22 vehicle headlights. extends a wire 24 which is provided with branches Attempts have been made to control the head- 25 each of which is connected to one terminal of lights of a vehicle by the light rays from the a filament 26 of one of the headlights II and I2, 5 headlights of an approaching vehicle acting upon these filaments being the dim light filaments of a light sensitive cell, but such attempts have had such a headlight and located below the focus of for their object to efl'ect dimming of the headthe headlight reflector. Similarly the contact lights and have been very intricate, requiring a 23 is connected by a wire 21 through branches number of batteries in some instances, several 28 through the bright light filaments 29 of the 10 relays in other instances, and in general being headlights which are located at the focus oi the quite complicated. lamp reflectors. The'filaments 26 and 29 are con- One important object of the present invention nected in multiple to a ground wire 30 grounded is to provide a device for the purpose set forth at 3|. From the contact i9 extends a wire 32 wherein but little addition to the equipment comwhich leads to the parking light l3. From the 15 mon to automobiles is necessary for the effective contact ill a wire 33 leads to a fixed contact 34 operation of automatic headlight control. engageable by a movable contact 35 which is con- A second important object of the invention is nected by a wire 36 with the stop light l4. The to provide apparatus for this purpose having stop light l4 and parking light l3 are grounded as great S p ty a using as s Sole Source Of at 31. At 38 is a transformer having a primary 20 Power e Ordinary Storage e y With Which winding 39 which has one terminal connected by all aut m le a quipp da. wire 40 with the wire i6 and thus with the A third imp rtant object f th inv ti i t positive terminal of the battery in. The other prov d a novel v e of this kind wherein a terminal of the primary winding 39 is connected single triode tube controls a single relay and by a wire 4| with a ground 42. The secondary 25 this. 111mm. efieoilstiltmg 0f the headlamp beam 43 of this transformer has one terminal conon the approach of another vehicle with its headt d by a wire 44 with one terminal of a high lights in luminous C0nditi0hresistance 45. At 46 is a triode tube having a fila- With the ab v end' Objects in V w, the men-t 41, a grid 48 and a plate 49. One terminal invention consists in general of certain novel f the filament 41 is connected by a wire 50 with 30 arrangements of electrical instrumentalities and th aining terminal of the resistance 45. The novel circuit connections therebetween as hereth r ter inal of the filament 4'! is connected by inafter fully described, illustrated in the accoma wire 5| t one terminal of relatively low p y n drawi and p ti ula ly po nt d out in sistance 52 which has its other terminal connected the ClaimS- by a wire 53 with the remaining terminal of the 35 In the acc pa y drawing like Characters secondary winding 43. At 54 is a relay magnet of reference indicate like parts in the different d the movable contact 2i forms the armature Views, for this magnet being normally held in engage- Fi ure 1 is awiring diagram sh wi g the difi ment with the contact 23 by a spring 55 but,

cut instrumentalities by conventional symbols wh n the magnet 54 is energized, being moved and also showin th vari us c u t connections into contact with the fixed contact 32. The plate between c instrumentalities- 49 is connected by a wire 56 with one terminal of Figure 2 is a front elevation of an automobile th magnet, 54, From th other t i of t radiator showing a light sensitive cell, such as is magnet 54 a, wire 51 leads to one terminal of a.

5 used in th s invention. Positioned thereenlight sensitive cell 58 having its remaining ter- 5 In the embodiment of the invention illustrated inal connected by a wire 59 with the grid 48.

herein the usual automobile storage battery is A wir 60 lead from the wire 59 to one terminal indicat d at the usual headlamps at H and of a resistance 6i which has its other terminal the pa amp at and the stop lamp at connected by a wire 62 with a contact 63 trav- The negative terminal of the battery I0 is ersing the resistance 52 so that a bridge of vari- 50 grounded as at I5. The positive terminal of the able i t e is formed b tw th secondary battery 10 is connected by a wire [6 with a movwinding 43 and t who 59, Also bridge wire able contact I! capable of being selectively posi- 61 connects the wire 51 with the wire 44 and thus tioned on the fixed contacts and I9. The fixed with the one terminal of the. secondary winding contact I8 is connected by the wire 20 with a 43. Parking lights 64 are connected by wires 65 55 to a wire 65 which is in turn connected to the wire 52.

Under the foregoing circumstances so long as the relay magnet 54 is not energized and with the contact Il closed on the contact l8 current will flow from the battery ||l through the wire l8, contact ll, contact I8, con-tact 2|, contact 23, wire 21, branches 25, bright filaments 29, wire 30, ground 3|, and ground If: back to the battery I0. However, if the light from an approaching car afiects the cell 55 then current will flow from the battery Ill through the wire l6, wire in. primary 39 of the induction coil 38, wire 4|, ound l2 and ground l5 back to the battery II).

This circuit is constant at all times and current will also flow from one terminal oi the secondary I! through wire 44, resistance 45, wire 50, filament 41, wire 5|, resistance 52, wire 52 and back to the secondary 53. With the cell 55 being afi'ected by the approaching headlight current will also flow through the circuit formed by the grid 45, wire 59, cell 58, wire 51, magnet 54, wire 55, and plate 49. This will, of course, energize the magnet 54 which will cause the armature contact 2| to move out of engagement with the contact 22 and into engagement with contact 22. This will, course, open the circuit through the bright filaments 29 and current will now fiow from the battery in through the wire I6, contact ll, contact l8, wire 20, contact 2|, contact 22, wire 24, branches 25, dim'fllaments 26, wire 80, ground 3|, and ground l back to the battery ill. The filaments 26 being located below the foci of the lamps the light beam from the headlights will not only be dim but will be inclined downward.

Obviously if it is desired to operate the stop light it is merely necessary to move the contact 35, which is generally a foot brake actuated contact, into engagement with the contact 24. Also should it be desired to operate the parking lights it is merely necessary to shift the manual contact |I out of engagement with the headlight contact l8 and into engagement with the parking contact l9.

What is claimed is:

1. In combination. a motor vehicle headlight system including bright and dim dual filament headlights; a parking light system; a common source of power; means including a light sensitive cell for automatically dimming said lights in response to the approach of an oncoming vehicle comprising an electromagnetic switch normally closing the bright filament circuit; a triode tube having plate, filament and grid elements; a secondary source of power energized from said common source; said cell electrically connected to said grid and to said secondary source of power and to the magnet 01 said switch and adapted to control the grid bias of said triode in response to the light rays of oncoming vehicles, whereby to efiect the lighting oi the dim filaments in said headlights; and a manual switch operable to selectively close the headlight filament circuits or the parking light circuit connections, whereby the headlight filament circuits are selectively operable automatically under the control 01 said light sensitive cell, or the parking light system alone is energized under said manual control.

2. In combination a motor vehicle headlight system including bright and dim dual filament headlights; a parking light system; a common source of power; manual means for selectively energizing either the parking light system or the headlight system; means for automatically dimming said lights in response to the approach of an oncoming vehicle comprising an electromagnetic switch normally closing the bright filament circuit; a triode tube having plate, filament and grid elements; a secondary source of power energized from said common source; relatively high and low resistance elements connecting said filament in series with said secondary source of power; a circuit in series with said secondary source of power including the electromagnet of said switch, said plate, and the relatively low resistance part of the filament circuit; a variable resistance circuit connecting said grid to said low resistance element; and a series circuit including a light sensitive cell connected between said grid and the common point between the high resistance element and the terminal of the secondary source or power, adapted to control the grid bias of said triode in response to the effect oilight rays from oncoming vehicles, whereby to automatically effect the selective lighting of the filaments in said headlights.

3. In combination a system for responding to light impulses comprising a triode tube having plate filament and grid elements; a source or power; relatively high and low resistance elements connecting said filament in series with said source of power; a circuit in series with said source of power including electro-magnetic means, said plate and the relatively low resistance part of the filament circuit; a variable resistance circuit connecting said grid to said low resistance element; and a series circuit including said light sensitive cell interconnecting said grid and the common point between the high resistance element and the terminal 01 said source of power, adapted to control the grid bias of said triode in response to the eflect of light rays from some source.

RUSSEL E. ALLEY. 

